Improvement in the manufacture of sulphuric acid



A. I-I. TAIT, O F N E YORK,`N. Y.

Lezers' Patent ivo. 86,8871, dma Fama/ry 9, 1869. i

rMPRovnMnNT IN THE MANnrAcrU-Rn or' SULPHURIC ecm The Schedule referred to in 'these Letters Patent arid making part of the same.

To all fwhom fit may concern Be it known that I, A. H. TAIT, of the city, county, and State of New York, have invented a new and useful Improvement in the Manufacture of Sulphuric Acid and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled in the art to make and use the same, reference being had to the accompanying drawing, forming part of this specication, in which drawingp Figure l represents a sectional side elevation of the apparatus, which I have used in carrying out my invention.

Figure 2 is a plan or top view thereof.

Figure 3 is alongitudinal vertical section of the concentrator.

Figure 4 is a plan or top -vilew of the same.

Similar letters indicate corresponding parts.

This invention is based on the discovery that sul- -phurous acid, (802,) when compressed into a fluid state and' brought in contact with nitrous acid, (NO3) also compressed-into a iiuid state in the presence of oxygen and steam, will produce sulphuric acid (S03) much more readily and quickly than it does when brought in con tact with nitrous acid in a gaseous state, as usually practised in the manufacture of sulphuric acid; and, furthermore, by using the sulphurous acid in a fluid state, or under pressure, I am enabled to separate the nitrogen of the atmospheric air from it in a simple and 'ecient manner, and the loss of nitrogen-gases is materially reduced, or almost entirely prevented.

The apparatus which I use in carrying out my invention consists of a furnace, A, for the purpose ofv producing sulphurous-acid gas by burning sulphur 'or pyrites.

The gases evolved in the furnace A are passed into Y the first washer, B, for the purpose of 4separating the atmospheric impurities, and from this washer said gases are removed by the action of the pump C, which serves to force the Vsame into the second washer, D, and through this washer into the vessel E, in which the gases vare subjected-to a pressure of forty-five pounds per square inch, so that the vsulphurous acid becomes fluid.

The lower part of the vessel E connects, by a pipe and cock, a, with the vessel F, in which the fluid sulphurous acid is collected.

In the upper portion of the vessel E is a cock, h, and when the pressure in this Vessel has reached the desired point for the compression of the sulphurous acid, said cock is opened gently, while the cock a is closed, and the nitrogen-gas which ismixed with the sulphurous gas evolved from the furnace A, is let off, while the fluid sulphurous acid is let down into the vessel F.

Vhen a sufficient quantity of fluid sulphnrous acid has collected in the vessel F, the pipe c is opened, which extends from the bottom part of said vessel to the coilc, situated in the washer D, and the fluid suland being freed from nitrogen, and other impurities, is

conducted into Vthe chamber G, which is supplied with nitric-oxide vapors, through a pipe, x, with steam from the boiler H, and with atmospheric air, or with pure oxygen, by means of a force-pump, I, which, when pure oxygen is used, also serves to produce the required pressure in said chamber, so that the sulphurous-acid gas will become fluid The nitrous oxide, (N025 on coming in contact with oxygen, inthe presence of steam or moisture, readily takes up another equivalent of oxygen, audforms nitrous acid, (N 03,) which, at the pressure existing in the chamber G, becomes duid, and mingles with the fluid sulphurous acid, but as soon as these two fluids come in contact, the nitrous acid parts witha portion of its oxy gen, which combines with an equivalent portion of the sulphurous acid, and forms' sulphuric acid, while the nitrous acid is thereby reconverted into nitrous oxide, which, being non-condensable by pressure, rises inthe rgaseous form, takes up another quantity of oxygen,

forming again fluid nitrous acid, and so forth, until all the sulphurous acid in the chamber has been converted into sulphuric acid.

If, instead of pure oxygen, ordinary atmosphericair is introduced into the chamber G, `the pressure in said chamber is not kept upto a point suicient to liquefy the sulphnrous acid, but only to about four to ten pounds per square inch, sufficient to facilitate the union of the gases,` and pass oii' the nitrogen of the air, and a portion of the nitrous acid through the receivers P P, where the latter is recovered and returned to the chamber.

Ihe connection between the chamber and receivers is effected by a pipe, or chimney, which is provided with a valve, loaded to the required pressure, but when pure oxygen is used in the chamber G, said chimney is not required.

In either case, however, whether atmospheric air or pure oxygen is introduced in the chamber, the sulphurous acid is entirely freed from the nitrogen mixed therewith, when it escapes om the furnace, bythe action of the vessels E F and pump O, as previously described,

and since the nitrogen, if not separated from the sulphurous acid, takes up nearly four--fthsof the space of the chamber, and furthermore, when it passes off by the chimney, to make room for a fresh supply of atmospheric air to carry on the process, it takes with itl a large portion ofsulphurous acid and nitric vapors which are wasted and lost my process oiiers no small advantage over the old process.

The sulphuric acid formed in the chamber Gis concentrated by means of. hot air, as follows: A pump, J, is provided, which serves toforce acurof water to raise the gravity of the acid quickly to 66%o Baum.

A furnace, T, supplies a fresh quantity of sulphur- ,ous acid, which is washed in the vessel S, and then passed, with the heated air, through the chamber-acid in the vessel L, so that all traces o f nitric acid drawn ci* from the chamber are got rid of.

The acid contained in the air passing ofi" from the` vessel L is condensed in a coil situated in a coolingvessel, M and it collects in the receiver N.

Having thus described my invention,

What I claim as new, and desire to secure by Letters Patent, is-

1. The Within-described process of freeing snlphurous acid from nitrogen, previous to introducing the same into the chamber, by liquefyin'gvthesulphnric 4. Exposing snlphurous-acid gas to the action of Ynitric oxide, atmospheric air, and steam, under pressure, as set forth.

5. Exposing the snlphurous acid in a uid state to the action of nitric oxide, oxygen, and steam, substantially in the manner herein described.

6. Passing a current of heated air through the chamber-acid, substantially as and for the purpose setforth.

7. Injeeting with the heated air a current of sul? phurous acid into the vessel, partially lled with the chamber-acid, substantially as and for the Ypurpose described. v

. A. H. TAIT. Witnesses:

W. HAUFF, ERNEST F. KAs'rEnHUBER. 

